Chemical heating pad



April 1l, 1939. F. REYNOLDS CHEMICAL HEATING PAD Filed July 26, 1957 FILE- L- FIE 4 FIC-3 5...-

. VINVENTOR. Freder/'c ,@eynO/o/ s ATTORNIY.

Patented Apr. 11, 1939 UNITED STATES PATENT OFFICE aisas'zs enmarcar. HEATING PAD Application July 26, 1937, Serial'No. 155,746

3Claims.

This invention relates generally to the construction of so-called chemical heating pads.

More particularly 'it relates to pads suitable for carrying out heating operations in permanent hair waving.

So-called chemical heating pads, such as are suitable for permanent hair waving, make use of an exothermic reaction between Vcertain chemicals, to furnish suiiicient heat for a waving operation. The type of pad employed for this purpose in the past, has made use of a metal foil envelope or sachet, containing the necessary chemicals in dry powdered or granular form. In using such a pad the chemicals are moistened with water, immediately before applying the pad about a wound strand of hair. Pads of this kind are subject to several serious disadvantages. 'I'hey are relatively expensive to manufacture, because of the use of metal foil envelopes or sachets containing the powdered chemicals. They are subject to relatively rapid deterioration when exposed to the air, due to more or less absorption of moisture from the atmosphere, with the result that some or all of the chemical action takes place before the pads are used.` Because of such deterioration it is common to supply such pads to the trade in relatively expensive sealed containers. However, even with this practice the pads are subject to deterioration, particularly since the containers may not at all times be air-tight.

It is an object of the present invention to provide a simple chemical heating pad, suitable for permanent hair waving, characterized particularly by the absence of chemicals in powdered or granular form within a foil envelope. In carrying out the present invention the reacting elements consist of a sheet of aluminum, in conjunction with a solution containing chemicals capable of exothermic reaction with the aluminum. The solution is carried by a sheet of absorbent material, to which it can be applied immediately before a waving operation.

A further object of the invention is to provide a chemical heating pad, suitable for permanent hair waving, which will not deteriorate in any way when stored over long periods of time, even though exposed to the atmosphere.

Further objects of the invention will appear from the following description in which the preferred embodiment of the invention has been set forth in detail in conjunction vwith the accompanying drawing:

Referring to the drawing:

Fig. 1 is a side elevational view, showing a pad (Cl. 13b-46.2)

in accordance with the present invention. applied to wound hair.

Fig. 2 is a fragmentary cross-sectional view of a simple form of pad, on an enlarged scale.

Fig. 3 is a fragmentary cross-sectional view of 5 a modiied form of pad, on an enlarged scale.

Fig. 4 is a fragmentary cross-sectional view of another form of pad, on an enlarged scale.

Fig. 5 is a perspective view illustrating a pad formed of composite elements, substantially as 10 illustrated in Fig. 4.

Fig. 6 is a view similar to Fig. 5, but showing a modification where an added amount of heat is desired.

- The present invention is predicated upon my 15 discovery that if a sheet of absorbent material like felt, flannel or blotting paper, is soaked with a suitable chemical solution, and then placed in contact with one side of a sheet of aluminum, a controlled exothermic chemical reaction can pro- 20 ceed between the chemical in the solution and the aluminum, with continuance of this chemical reaction until one of the essential elements of the reaction, as for example the aluminum sheet, is depleted. 25

Referring to the simplied arrangement of Fig. 2, I have shown a sheet of aluminum IIJ. one side of which is in contact with a sheet Il of absorbent material, like blotting paper, felt or ilannel. It is the absorbent material Il to which is applied 30 a solution of suitable chemicals. capable of exothermic reaction with the aluminum. The solution employed may vary according to requirements, but in general it can contain a soluble salt of a heavy metal, like copper sulphate. together 35 with an active oxidizing salt like sodium or potassium chlorate. In preparing the chemical solution amounts of each salt should be added suilicient to saturate the solution. For example I can employ about 30 grams of copper sulphate, and 40 about '75 grams of sodium chlorate, together with about grams of water. The sheet of absorbent material Il can be saturated with the solution before being applied to the aluminum sheet l0, or the solution can be applied to the absorb- 45 ent sheet after the sheet has been applied as shown in Fig. 2. In any event a reaction immediately commences, and with the solution specified the reaction does not cease until substantially all of the aluminum sheet has been disintegrated, 50 or the dissolved chemicals depleted. 'I'he sheet I0 can be embossed to provide a greater surface in contact with the solution, or it may be corrugated, pleated or otherwise formed for the same Purpose- 55 Fig. 3 is substantially the same as Fig. 2, except that in this instance two sheets III of aluminum are placed upon opposite sides of the sheet II of absorbent material. Here again the sheet II can be saturated with the solution before the sheets I are applied upon opposite sides of the same. or sheet II can be applied upon one of the sheets III,

solution applied, and then the other sheet I0 apl plied.

In using an assembly such as described with respect to Figs. 2 and 3 for a permanent hair waving operation, it is desirable to provide some form of protection over both sides of the assembly, in order to preclude contact of chemical with the hair. Assemblies of this sort are illustrated in Figs. 4 and 5. The assembly of Fig. 4 makes use of two sheets of readily bendable aluminum III with an intervening sheet of absorbent material II, together with a protecting covering consisting of two outer metal foil sheets I2, with these sheets provided with liners I3 of paper parchment. The outer foil sheets I2 can be of aluminum, without taking part in the chemical reaction to any substantial degree. The parchment paper I3 adequately prevents contact oi' chemical with the outer aluminum foil covering I2, and at the same time aiiords protection against the contact of chemical with the hair. Assuming that an assembly of this kind is applied about a wound strand of hair, which is made possible because of the bendable or deformable nature'of the material employed, the heat developed is adequately and effectively transferred to the wound hair, through the intervening sheets of parchment and metal i'oil.

Instead of using separate sheets of material as indicated in Fig. 4, a bound assembly o! sheets can be employed as shown in Fig. 5. Thus in this instance the sheets Ina, corresponding to the sheets I0 or Figs. 2 to 4 inclusive, together with' the outer foil sheets Ila, and their associated pachment paper liners Ila, have their corresponding edges bound together as indicated at I6, thus forming a convenient assembly for supplying to the trade. `'Ihe sheet IIa of absorbent material may or may not be permanently attached to this assembly. If it is not permanently attached, the sheet IIa is moistened with the chemical solution, and then applied between the aluminum sheets Illa, as shown in Fig. 5, after l which the pad is bent about the wound hair for a waving operation. While the manner in which chemically heated pads are applied to wound hair is well known in the art, application as in Cro'- quignole permanent hair waving is indicated in Fig. 1. In this instance a pad A is employed as shown in Fig. 5, and this pad is applied about a curler I1, upon which a ilattened strand of hair is wound. 'I'he pad can be retained in good thermal contact with the wound hair, by a suitable spring clip. The curler is shown supported bya conventional Croquignole hair waving protector I8. As is well known in the art, similar application can be made to curlers of the spiral type, with the only possible variation that the dimensions may be altered, in accordance with the greater length of curler rod employed. Before applying the heating pad the hair is moistened with hair waving solution, and if desired a sheet of flannel saturated with hair waving solution can be interposed between the pad and the hair.

The pad shown in Fig. 6 is similar to that oi Fig. 5, except that in this case three aluminum sheets Illa have been employed, in place of two as in Fig. 5. These three sheets will serve to accommodate two sheets IIa of absorbent material, whereby a somewhat greater amount of sheets can be provided, for the waving operation.

It will be apparent that my pad obviates the disadvantages previously outlined with respect to pads making use of a foil envelope, containing powdered or granulated chemicals. There can be no deterioration upon exposure to the atmosphere, because the chemical solution can be kept in well stoppered bottles, out of contact with the air at all times. Manufacture is a comparatively simple operation, which does not involve the handling of powdered material, and does not involve the vmaking of an air-tight foil envelope.

I claim:

l. In a chemical heating pad, a sheet of readily bendable aluminum, a readily bendable sheet of absorbent material adapted to be disposed in contact with at least one face of the sheet of aluminum, said sheet of absorbent material being adapted to contain a solution capable of exothermic reaction with the aluminum, and a protective covering extending over one side of the assembly, said covering being substantially inert with respect to said solution and being attached to the assembly formed by the sheets of aluminum and absorbent material.

2. In a chemical heating pad, an assembly comprising a readily bendable sheet of aluminum, a readily bendable sheet of absorbent material adapted to bev disposed in contact with at least one face oi.' the aluminum sheet, said absorbent material being adapted to contain a solution capable of exothermic reaction with the aluminum, a protective sheet of parchment paper extending over one side of the assembly, and a sheet of metal foil extending over said parchment sheet, both said vprotective sheet and said last named sheet of foil being attached to the assembly formed by the first named sheets of aluminum and absorbent material.

3. In a chemical pad for permanent hair waving, a sheet of readily bendable aluminum, a readily bendable sheet of absorbent material disposed in contact with at least one face of the aluminum sheet, said material being adapted to contain a solution capable of exothermic reaction with the aluminum, a sheet of parchment paper extending over the other face of the aluminum sheet, and heat conducting metal foil extending over the parchment paper, both said protective sheet and said last named sheet of foil being attached to the assembly formed by the first named sheets of aluminum and absorbent material.

FREDERICK L. REYNOLDS. 

